To extrude plastics, one may use an extruder, sheet die, and an embossing-stack. In one example, a thermoplastic adhesive is extruded through the die into cylinders of the embossing-stack, where the adhesive is formed into a film. The surface of the film is embossed with a finish and then the film is cooled. The cylinders of the embossing-stack have an embossed surface, which they impart onto a thermoplastic sheet. The cooled thermoplastic sheet may be collected on a roll or cut using a single layer of interleaf material to separate consecutive wraps or layers.
In another example, film is extruded from an extruder through sheet die onto one interleaf while the film is still thermoplastic. From a position that is near to the sheet die, the film and the interleaf layer are simultaneously pulled by a set of nip rolls that press the film and interleaf layer together while the film is still relatively warm. During this process, the texture of the interleaf layer is impressed in the film. The film and interleaf layer are lightly bonded together so that the interleaf layer can later be peeled.
It is believed that in the above method of preparing a thermoplastic sheet, stress is added to the sheet when the film is pulled off of the collection roll and this stress adversely affects the performance of the sheet in the preparation of a laminate. Consequently, the adverse effects from the stress may show up in the final laminated product.